The present disclosure is related to an objective lens for endoscopes and to an endoscope.
Conventionally, endoscopes are employed to observe and treat the interiors of patients' bodies in the medical field. Objective lenses for use in endoscopes are disclosed in Japanese Patent No. 4846752 and Japanese Patent No. 5485482. Japanese Patent No. 4846752 discloses a lens system having a three lens configuration, which includes, in order from the object side to the image side, a negative lens, an aperture stop, a planoconvex lens having a convex surface toward the image side, and a planoconvex lens having a convex surface toward the object side. Japanese Patent No. 5485482 discloses a lens system having a three lens configuration, which includes, in order from the object side to the image side, an aperture stop, a positive lens, and a cemented lens.